Glass Mapper: Does the number of mapped fields have a performance impact?

Recently at work, the discussion arose if the number of fields mapped from Sitecore Items to our models would have a performance impact. The question was if we should limit the number of mapped properties in our IGlassBase interface to gain performance.

I did a simple test by mapping an item to a test interface (IGlassBaseTest) and measuring the execution time of these lines 50’000 times.

Conclusion

While the first two tests didn’t show a significant difference, the last test adds roughly 10ms to our total. But remeber, that’s only 0.0002ms per execution which can also be considered insignificant in my opinion.
Based on these tests I can say, that the number of fields mapped by Glass Mapper only has a negligible impact on performance.